Propelling mechanism for boats



H. M. F'OHLER PROPELLING MECHANISM FQR BOATS 9 Filed Sept. 10, 1925 Half'man 0111 ET Patented Dec. 1, 1925.

UNITED STATES HERMAN M. IPOI-ILER, OF MILWAUKEE, WISCONSIN.

PROIPELLING MECHAIQZSLVE FOR BOATS.

Application filed September To all whom it may concern:

Be it known that I, HERMAN M. POHLER, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Propelling Mechanism for Boats; and I do'hereby declare that the following is a full, clear, and exact description thereof.

This invention relates to propelling mechanism for boats.

Objects of this invention are to provide a propellingdevice for boats which may be driven by the operator in a very simple manner by means of pedals, and which will multiply the speed of rotation so that the propeller rotates a large number of times for one revolution of the pedals.

Further objects are to provide a very simple type of device in which a spiral worm and worm wheel are employed for securing the increase in speed of rotation for the propeller shaft, and which is so constructed that it may be very readily mounted in any of the standard types of boats.

A further object is to provide a device adapted to be driven by the feet of the operator in which provision is made for ad justing the device to accommodate operators of different sizes, and in which this adjustability is secured in a very simple and effective manner.

An embodiment of the invention is shown in the accompanying drawings, in which Figure 1 is a longitudinal sectional view through the rear portion of a boat, such as a canoe, fitted with the device.

Figure 2 is a partial sectional view through the apparatus.

Figure 3 is a sectional view through the propeller hub and associated bearing.

Referring to the drawings, it will be seen that any suitable relatively small boat is indicated by the reference character 1, and that this boat has an upwardly projecting standard 2 secured to a base. The standard 2 is provided with a portion 2, as indicated in Figure l, which is adapted to slide upon the base 3 secured to the bottom of the boat. The base 3 is provided with a slanting upper face 4 and it is to be noted that the base 3 is provided with an apertured ear 3 through which an adjusting screw 4 passes, such adjusting screw being threaded into a portion of the member 2, as shown in Figure 1. In ad- 10, 1925. Serial No. 55,538.

justing the device for operators of different sizes, it is a simple matter to move the standard 2 forwardly or rearwardly to move the rest of the apparatus into the most effective position for the operator as will appear as the'description proceeds.

The upper end of the standard is provided with a housing 5 within which the relatively steep or high pitch spiral worm 6 is positioned, such worm being formed integrally upon the propeller shaft 7. This propeller shaft is provided with a reduced portion 8 at its inner end which is carried within a suitable bearing, and preferably thrust bearings 9 and 10 are provided on opposite sides of the bearing for the reduced portion 8, as illustrated most clearly in Figure 2. The other end of the worm housing 5 is provided with a threaded extension 11 which is coupled by means of a union 12 to a pipe 13, or housing for the propeller shaft.

The upper part of the housing 5 is circular, as indicated at 14, and houses the spiral worm wheel 15. This spiral worm wheel meshes with the spiral worm 9 and is keyed to a transverse shaft 16, such shaft projecting outwardly from opposite ends of the casing 14. Preferably, the casing 14 is made in halves to permit its ready separation and to facilitate assembly. If desired, the casing 14 may be provided with a boss 14 on its upper side. support for racks or other devices that may be desired.

The outer end of the shaft 16 carries crank arms 17 which are provided with pedals 18. The device is so located that the operator may conveniently sit upon the rear seat 19 with his feet upon the pedals 18 and may easily operate the device.

The rear end of the propeller shaft and propeller shaft housing project through a fitting 20. The propeller shaft housing is screwed into the hub 21 of a propeller guard 22 mounted upon the outer side of the boat. This hub constitutes a bearing for the propeller shaft 7. This bearing is provided with an oil duct 23 into which an oiler may be screwed, as indicated at24 in Figure 1.

The propeller 25 is mounted upon the outer end of the propeller shaft 7 and is secured thereto by means of a pin 26, such pin passing through the shaft and through the hub of the propeller. The propeller is held upon the shaft 7 by means This boss affords a secure of the nut 27. Any suitable type of water tight joint may be formed between the propeller hub and the bearing 21. For example, recesses 28 and 29 may be formed in the propeller hub and in the hearing 21, and suitable packing 30 may be positioned Within these recesses, as indicated in Figure 3. This provides a very simple construction for attaining a water tight joint, but it is to be understood that this particular type of joint may be varied without departing from the spirit of the invention.

It is to be particularly noted that bevel gearing is avoided by this construction, and a spiral worm and worm wheel are employed. It has been found that the spiral Worm and worm wheel in this type of mechanism can be made very much quieter than other types of gearing and also can be made with very high efficiency. Further, by the use of the spiral worm and worm wheel, a very compact structure results.

It is to be noted that when the adjusting screw 4 is rotated, the casing 14, the tubular member 18 and the entire apparatus carried thereby slides freely forwardly or backwardly depending upon rotation of the screw. It is to be noted that the slanting face 4L parallels the slant of the propeller shaft and consequently the tubular member 18 may freely slide through the bearing 20 during this adjustment.

It will be seen that a very simple and sturdy type of propelling mechanism for boats has been provided which may be readily operated by means of the feet of the user without'requiring much effort on his part, and which is noiseless in operation as the gearing is preferably of the cut gear type and also runs in oil or grease. Thus the boat is admirably adapted for approaching easily alarmed game as in hunting.

Although the invention has been described in considerable detail, it is to be understood that the invention may be variously embodied and is, therefore, to be limited only as claimed.

I claim:

Propelling mechanism for a boat comprisinga base secured to the bottom of the boat, a standard carried by said base, a housing carried by the upper end of the standard, a spiral worm wheel carried within said housing, a transverse shaft secured to said wheel and projecting from opposite sides of said housing, a pair of crank arms secured to the projecting ends of said shaft, a propeller shaft projecting into said housing and extending rearwardly therefrom through the back of the boat, a spiral worm on said shaft and meshing with said spiral worm wheel, a bearing adjacent the rear end of said propeller shaft, a tubular housing for the propeller shaft extending from said first mentioned housing to the said bearing, a propeller secured to the rear end of said propeller shaft, and means for adjusting the standard upon the base.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of Wisconsin.

HERMAN M. POHLER. 

